Estimation of Titanium Dioxide Intake by Diet and Stool Assessment among US Healthy Adults.

BACKGROUND: Titanium dioxide (TiO2/E171) is used in foods primarily as a whitening agent. Little is known regarding TiO2 exposure in the United States. OBJECTIVES: To quantify stool TiO2 content among US adults and evaluate its association with estimated intake. METHODS: Adults participated in phase 1 [three 24-h dietary recalls (DRs) and stool TiO2 measured from 3 matched samples (n = 52)] and/or phase 2 [tailored FFQ and stool TiO2 measured from 3 samples over 3 mo (n = 61)]. TiO2 in foods was estimated from a database, and concentration in 49 additional foods and 339 stool samples were quantified using inductively coupled plasma mass spectrometry. Associations between dietary and stool TiO2 were assessed by log-linear multivariable regression. USDA food groups (n = 49, servings/d) were related to stool TiO2 by stepwise regression. RESULTS: TiO2 food content varied by brand. Mean TiO2 intake from three 24-h DRs [0.19 ± 0.31 mg/(kg body weight · d)] was lower than from the FFQ [0.30 ± 0.21 mg/(kg body weight · d)]. Dietary TiO2 was not predictive of stool TiO2, in phase 1 or phase 2, 10^(ß) per 10 times higher dietary TiO2: 1.138 [10^(95% CI): 0.635, 2.037, P = 0.66] and 0.628 [10^(95% CI): 0.206, 1.910, P = 0.41], respectively. Food groups related to stool TiO2 were 1) milk desserts, sauces, and gravies [10^(ß) per servings/d: 3.361; 10^(95% CI): 0.312, 36.163; P = 0.002] and 2) yeast breads [10^(ß): 1.430; 10^(95% CI): 0.709, 2.884; P = 0.002] in phase 1 and 1) cream and cream substitutes [10^(ß) = 10.925; 10^(95% CI): 1.952, 61.137; P = 0.01] and 2) milk and milk drinks [10^(ß) = 0.306; 10^(95% CI): 0.086, 1.092, P = 0.07] in phase 2. CONCLUSIONS: Intake of certain foods was associated with higher stool TiO2 content. There is a need for valid estimation of TiO2 intakes via the improvement of a dietary assessment method and a TiO2 food composition database. Future research should assess whether high stool TiO2 content is related to adverse health outcomes.

Stool titanium dioxide is positively associated with stool alpha-1 antitrypsin and calprotectin in young healthy adults.

Titanium dioxide (TiO2/E171) is used widely in foods, primarily as a food additive. Animal models have shown that chronic TiO2 exposure may disturb homeostasis of the gastrointestinal tract by increasing gut permeability, inducing gut inflammation, and increasing the likelihood of microbial infection. Adults have a wide range of ingested TiO2,which span two to three orders of magnitude, with a small portion of individuals consuming near gram quantities of TiO2/day. However, research on the health effects of chronic ingestion of TiO2/E171 in humans is limited. We hypothesized that regularly ingested TiO2/E171 is associated with increased gut inflammation and gut permeability in healthy adults. We tested this hypothesis in a cross-sectional design by measuring clinically established stool markers of gut inflammation (calprotectin, lactoferrin) and gut permeability (alpha-1 antitrypsin; A1AT) in 35 healthy adults, and comparing these markers between relatively high and low TiO2 exposure groups. Participants were stratified by TiO2 stool content (high dry stool TiO2 content: 0.95-9.92 µg/mg, n = 20; low content: 0.01-0.04 µg/mg; n = 15). Differences in gut health markers were tested between high and low exposure groups by independent samples t-test or Mann-Whitney U test. Multivariable linear regression was used to assess the association between TiO2 in dry stool and measured stool alpha-1 antitrypsin (A1AT). Participants in the high stool TiO2 group had greater stool A1AT (42.7 ± 21.6 mg/dL; median: 38.3; range: 1.0-49.2 mg/dL), compared to the low TiO2 group (22.8 ± 13.6 mg/dL; median: 20.9; range: 8.7-93.0 mg/dL), P = 0.003. There was also greater stool calprotectin in the high TiO2 group (51.4 ± 48.6 µg/g; median 29.2 µg/g; range: 15.3-199.0 µg/g) than in the low group (47.5 ± 63.3 µg/g; median 18.8 µg/g; range: 1.6-198.1 µg/g), P = 0.04. No clear difference was observed for lactoferrin (high TiO2 group 1.6 ± 2.1 µg/g; median: 0.68 µg/g; range: 0.01-7.7 µg/g, low TiO2 group: 1.3 ± 2.6 µg/g; median: 0.2; range: 0.01-7.6 µg/g) (P = 0.15). A1AT concentration was positively associated with stool TiO2, after adjusting for confounders (ß ± SE: 19.6 ± 7.2; P = 0.01) R2 = 0.38). Community dwelling, healthy adults with the highest TiO2 stool content had higher stool A1AT and calprotectin, compared to those with the lowest TiO2 stool content. Ongoing research is needed to validate these observations in larger groups, and to determine the long-term effects of ingested TiO2 on human gut health, using these and additional health endpoints.

Protein Source and Muscle Health in Older Adults: A Literature Review.

Research shows that higher dietary protein of up to 1.2 g/kgbodyweight/day may help prevent sarcopenia and maintain musculoskeletal health in older individuals. Achieving higher daily dietary protein levels is challenging, particularly for older adults with declining appetites and underlying health conditions. The negative impact of these limitations on aging muscle may be circumvented through the consumption of high-quality sources of protein and/or supplementation. Currently, there is a debate regarding whether source of protein differentially affects musculoskeletal health in older adults. Whey and soy protein have been used as the most common high-quality proteins in recent literature. However, there is growing consumer demand for additional plant-sourced dietary protein options. For example, pea protein is rapidly gaining popularity among consumers, despite little to no research regarding its long-term impact on muscle health. Therefore, the objectives of this review are to: (1) review current literature from the past decade evaluating whether specific source(s) of dietary protein provide maximum benefit to muscle health in older adults; and (2) highlight the need for future research specific to underrepresented plant protein sources, such as pea protein, to then provide clearer messaging surrounding plant-sourced versus animal-sourced protein and their effects on the aging musculoskeletal system.